Synchronoscope



Feb. '21, 19383 K. H. MAY

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UNITED? STATES fl-PATEN TJ OFFICE.

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Application filed July 15, 1887, Serial lie.

10 from standard meter parts in a simple manner.

The features of my invention which are believed to be novel and patentable will 'be pointed out in the claims ap ended hereto. For a better understanding 0 my invention,

reference will be made in the following description to the accompanying drawing.

Referring to the drawing, t e single figure shows the preferred arrangement of the a paratus and its circuit connections to in icate the condition of synchronism between two alternating current systems indicated at 10 and 11. The synchronoscope comprises a rotatably mounted disc of conducting mateshaft is biased to a certain rotative position b one or more spiral springs one of which is s own at 14.

Whenthe synchronoscope is to .be of the I0 direct indicating type an indicator 15 is Se cured on the shaft and cooperates with the stationar scale 16 so' that the normal position of t a pointer as biased by the sprin s alone is on the central synchronizing indieating point of the scale.

Coo crating with the disc 12 are two simi lar in uction meter torque elements A and B with core parts 17 an 18 similar to those employed in standard watt-hour meters for the potentialand current cores respectively. These coreparts carry energizing coils 19, 20', 21 and22 The coil 19 on the E-sha ed core of the torque element A is connecte in serieswith thecoil 22 of the U-shaped core 4 of torque element B and across one ofthe sources, for example source 11. The coils 20v and 21 are simll' arlx connected in series across the source 10. damping device indicated at 23is preferably provided to dam arrangement.

' The torque of an induction meter element of the character shown at A or B is known to be protgortional to the roduct of the fluxes of e two of 0 element cutdisc productive of thi;

206,111, and in Germany August 81, 1920.

ting the disc multiplied by the'sineof the v angle b which the two fluxes are momentarily lsplaced with respect to each other. Thus,.i f E and E -represent the voltages of sources 10 and 11 respectively, and 9 the phase angle between these voltages, the torque of either element A or B would be proportional to E E sin 8 if it could be as sumed that the respective fluxes of the two parts 17 and 18 of such elements la behind the impressed electromotive force amounts.

Owing to the fact that the E-shaped core has a large leakage compared to the -shaped core, the fluxes of the two arts will be out ofphase by' the angle 9 w an the impressed electromotive forces E and E are infphase. As a consequence the tor no of either element will be proportional to E sin 6 when the voltages are in phase.

The two elements. A and B and their coils are similar so that the torque components E E sin 9 are equal in both and in accordance with the invention are arranged to oppose each other. The torque resultant of elements A'and B orr the disc then becomes proportional to E E [sin (6+6 +sin (9-6 By simple conversion the resultant torque appears as.2 E E cos 9 sin 9. Since 6 is the angle between E "andE the resultant torque y equal is zero when E and E are in phase, or in phase opposition, because then sin Q'is zero.

, At other times the torque will be or dependin upon whether E lags or leads E Thus, t e pointer 15 will oscillate back and forth across the scale 16 when the two voltages E and E are of difierent frequency. As the frequencies are equalized-theoscillations will become slower and when they are.

equal the pointer .will remainstationary at some point on thescale depending uponthe phase difference 9. When-the phases are in coincidence or in phase opposition the resultant torque will be zero and the pointer will return tothe middle of the scale.

To determine'whether it is phase coincidence or phase :pposition we maprovide a lamp23 energi from the mid e leg of a three-leg transformer 24 the outer legs of which are ener from the two sources in such manner at whenthe voltages are in phase the lamp lights. Thus, with the lamp ,2? lit and the'polnter 15 atits zero torque position the two sources are insynchromm.

The torque of the spring or springs 14 will be such as to restrain the s aft 13 from making a complete rotation or suitable stop may be provided for this purpose.

In accordance with the provisions of the patent statutes, I have described the prin- .ciple of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but

I deslre to have it'understood that the apparatus shown and described is only illustrative and that the invention may carried outby other means. 7

What I claim as new and desire to secure by Letters Patentof the United States, is 1. A synchronoscope having a rotatably mounted shaft provided with means for restraining it from making a complete revolution and to return it to a predetermined position, a pair of similar induction motor torque elements acting opposition upon :said shaft, said torque elements each having a pair of energizing coils, and two energizing circuits for said coils each including an energizing coil from each torqueelement.

2. A synchronoscope having a 'rotatabl 'mounted shaft, means for biasmg said sha to a predetermined rotative position, an induction disc secured to said shaft, a pair of similar induction motor torque elements acting in opposition upon said disc, each torque element comprising two electromagf netic members of difi'erent magnetic leakage characteristics, an energizing circuit for the electromagnetic members on the two, torque elements'having di-fierent magnetic leakage charaetertistics, and a similar energizing circuit for the remaining electromagnets on the two torque elements.

3. A synchronoscope having a rotatably mounted shaft resiliently'biased to a predetermined rotative position, an induction disc on said shaft, a pair of induction torque elements acting 'in op osition on said disc,

each comprising an shaped core and a U- shaped core with energrzlng coils for each -core, and a pair of energlzlng clrcu'lts each including an energizing coil on the E-sha core and an energlzing coil on the U-shaped core of the different torque elements.

4. In combination with two alternating current sources, a synchronoscope therefor having a pair of similar induction meter elements acting in op sition on a common rotatablymounted in 'cator system, each of said elements having a pair of electromag nets-0f diflerent magnetic leakage characteristics and energizing coils for said 'electromagnets, a circuit energized from one of said sources and connected in series with coils on the cores of different magnetic leak- KARL 11. MAY. 

